Reading down, Amazing Ampharos & Thinkman found hitboxes for Norfair in it's rel near FFD8,and shown the hex values used,which opened the door further for searching and editing for hitboxes in stage .rels.

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Values are stored in modules. Thinkaman and I found some in Norfair. Go to FFD8 and look nearby. 38a0XXXX is damage, 38e0XXXX angle, 3940XXXX base, 3900XXXX growth. This changes the hitboxes on the lava floor. E310 uses the same mapping (but they are listed in a different order!) and affects the lava walls. Trying to figure these files out further is proving very hard for me.

Default values for PTAD cars are 14h damage, 5ah angle, and some known kbg and bkb but Norfair is the only case I have so far of editing modules succssfully and changing in-game damage behavior.

It's in a slightly different format than PSA but editable all the same.